Coilcraft B0863-B Transformer for PoE Powered Devices
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SMT Transformer
for Power over Ethernet

  • Developed for Maxim MAX5941B PoE Interface/PWM Controller
  • IEEE 802.3af compliant PoE forward converter applications
  • Low profile, surface mount transformer
  • 3.3 V, 4 A output
  • 275 kHz switching frequency at a 50% duty cycle
  • 1500 Vrms isolation from primary, reset and bias to the secondary and drive
  • RoHS-compliant. 260°C compatible. Tin-silver over tin over nickel over phos bronze terminations


Part number1
Click to get parts
L min2
DCR max3
L max4
range (V)
Turns ratio5
pri : sec : reset : drive : bias
B0863-BL_ 165.0 0.061 (primary)
1.10 (reset)
1.29 (bias)
0.008 (sec)
0.023 (drive)
0.75 28 – 60 : 0.24 : 1 : 0.24 : 1.3 3.3 V, 4 A
1When ordering, please specify packaging code: e.g. B0863-BLD
  Packaging:D = 13" machine-ready reel
EIA 481 embossed plastic tape (200 parts per full reel).
B = Less than full reel
In tape, but not machine-ready. To have a leader and trailer added ($25 charge), use code letter D instead.
2 Inductance is for the primary, measured at 10 kHz, 0.1 Vrms, 0 Adc.
3 DCR for the secondary is measured with the windings connected in parallel. DCR measured at 25°C. For other operating temperatures, use this DCR at Temperature calculator.
4 Leakage inductance is for the primary with all other windings shorted.
5 Turns ratio is with the secondary windings connected in parallel.
6 Output is with the the secondary windings connected in parallel.
7 Ambient temperature range: –40°C to +85°C
8 Storage temperature range: Component: −40°C to +85°C
Tape and reel packaging: −40°C to +80°C
9 Resistance to soldering heat: Three reflows at >217°C for 90 seconds (+260°C ±5°C for 20 – 40 seconds), allowing parts to cool to room temperature between.
10 Electrical specifications at 25°C.
Refer to Soldering Coilcraft Components before soldering.
PCB washing: Tested to MIL-STD-202 Method 215 plus an additional aqueous wash. More info

Your comments and suggestions are welcome. Contact [email protected]
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Updated: April 16, 2018